After the sudden disappearance of her partner one summer in Corsica, Lou Colpé returns to Charleroi. Their home, a place where the absence is tangible, is transformed into a sanctuary. Everything there becomes a treasure and a ritual. She films what is reinvented every day: her survival. A moving manual for grief, Comme un château fort captivates with its luminosity, its humour and its masterful ode to friendship.